1. Field of the Invention
The present invention relates generally to subsea wellhead assemblies, more specifically assemblies having a conuit with an upper portion capable of disconnecting from a lower portion that has been cemented into the well.
2. Background of the Prior Art
Subsea wells typically have a low pressure wellhead housing with a string of conductor casing suspended therefrom. A high pressure wellhead housing lands with in the low pressure wellhead housing and supports another string of casing suspended into the well. Additional intermediate hangers and strings of casing are supported within the high pressure wellhead housing which extend to deeper depths within the subsea well. In a typical subsea well, the outer casing suspended from the low pressure wellhead housing is embedded into the seafloor to a predetermined depth below the mudline.
When the well is abandoned after completing the exploratory drilling, many laws and regulations require that there cannot be any structure protruding above the seafloor. Several of the intermediate strings of casing are cut below the mudline to allow removal of the upper portion of those strings. The conductor casing suspended from the low pressure wellhead housing must also be cut to remove the low pressure wellhead housing. Cutting the conductor casing can be time consuming and does not allow for the conductor casing above the cut to be reused.